Techniques for energy management in data processing apparatus are known. Energy management is particularly important in low power or mobile data processing apparatus applications. This is because in these applications there is generally provided a finite energy source, such as a battery. By managing the energy consumed it is possible to prolong the operation of the data processing apparatus. Equally, for conventionally powered data processing apparatus, managing the energy used by the data processing apparatus can reduce heat generation and provide for lower running costs.
In order to vary the energy consumed it is known to vary the performance of the data processing apparatus. Increasing the performance of the data processing apparatus increases the energy consumed, whilst reducing performance of data processing apparatus can reduce the energy consumed. The performance of a data processing apparatus is generally varied by altering the operating voltage and operating frequency of that data processing apparatus.
Accordingly, the energy consumed by the data processing apparatus can be varied in dependence on the particular operating state of the data processing apparatus. For example, when the data processing apparatus is in a dormant state it is known to reduce its performance, thereby minimising energy consumption and helping to maximise battery life. Equally, when the data processing apparatus is performing intensive operations it is known to maximise its performance, which increases the energy consumed by the data processing apparatus and decreases battery life.
Whilst these techniques enable energy to be actively managed, there remains further scope for improvement.
Accordingly, it is desired to provide an improved technique for energy management.